


sister/lover

by momo314



Category: Pocket Monsters: Sword & Shield | Pokemon Sword & Shield Versions
Genre: Bede shows up for a smidge, Creampie, Established Relationship, F/M, Jealousy, Multiple Orgasms, Post-Canon, Shower Sex, Sibling Incest, Underage Sex
Language: English
Status: Completed
Published: 2020-06-10
Updated: 2020-06-10
Packaged: 2021-03-03 20:41:06
Rating: Explicit
Warnings: Underage
Chapters: 1
Words: 4,921
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/24631720
Author URL: https://archiveofourown.org/users/momo314/pseuds/momo314
Summary: Piers has a bit of a jealous streak, and Marnie knows it.
Relationships: Mary | Marnie/Nezu | Piers
Comments: 5
Kudos: 48





	sister/lover

**Author's Note:**

> This fic has been in my WIPs for so many months, but I'm happy to finally finish it! And on Alia's birthday of all days, I hope you have a good one!
> 
> As usual, no ages are explicitly mentioned, though I tend to view them as 14 and 22.

"Big bro." Marnie popped her head into his room, where Piers was still lying in bed, slowly working himself to get up. He craned his head to promise her that he'd get on making breakfast in five more minutes, but lost the words when he saw her in the doorway. Rather than the long cutoff t-shirt she wore around the house (stolen from his closet years ago), Marnie was all dressed up like she was going somewhere. "I'm headin' out now," she said, confirming his suspicions.

Heading out...? It was probably the fact that he'd only opened his eyes twenty minutes ago that added to his confusion. "Where to?"

"Didn't I tell you my mate was stoppin' by today?" Marnie's expression was deeply unimpressed with him, which told him that she definitely had mentioned it before—maybe more than once. Oops. Now that he thought about it, she had asked if he minded her spending Saturday hanging around town with one of her friends. There was no way he could have said no, not when she'd been doing so much work as the newest Spikemuth Gym leader, even if he hoped they would have more time to themselves.

"Yeah, yeah, I remember now." He'd told her that he could use the extra day writing music for his big post-retirement tour, though now he was thinking about brainstorming in bed. "Have fun, Marn." She'd have a good time with Gloria.

Marnie gave a little smile in return. "Thanks." She looked down at her Rotomphone and ducked out of the room, calling out, "He'll be here any minute. Gotta go!"

There was the heavy thud of their loft door closing as Marnie left before the gravity of her words fully penetrated Piers's brain. Did she just say "he"? Piers knew he hadn't heard her incorrectly, and she didn't seem to have misspoken, so... it wasn't Gloria coming by? Thinking about it harder, she never did refer to the person coming by name, so Piers had stupidly assumed it was his little sister's friendly rival. Instead, it was a boy that Marnie was going to see. She'd invited a boy to come to Spikemuth for some reason?

It couldn't have been Hop—he was friendly with Piers and had exchanged numbers after the whole mess involving Dynamaxing Pok _é_ mon, and he would have mentioned it if he was planning to stop by. It had to be someone else. Surely Marnie would have told him who it was if he knew them well—so that cut out most of the Gym Leaders. Unless she was sneaking around behind his back? But Marnie was a smart girl. She wouldn't be so bold as to invite someone to Spikemuth and tell him about it if she was trying to keep it a secret. Besides, Marnie would never do something like that to him! She could get a little fussy and needy sometimes, but she was sweet and honest at her core.

Though, she did hold grudges particularly well... And she was still a bit hot over the tour he had planned across Galar without asking her permission first. Of course she would have said yes and been happy for him, but Piers had been so shocked about the opportunity that he'd agreed to it right away without mentioning it to her. That wasn't enough to make her do something to make him jealous. Right?

Piers couldn't get the thought out of his head. And—from a purely a brotherly perspective, it was normal to make sure your little sis was okay when she was meeting with a boy, yeah? Piers was out of bed before he knew it, pulling on a black jacket. He was just gonna check on Marnie (see who it was she was meeting with, make sure there was nothing going on between them) and go straight home, get straight to writing...

He found her right away, at the gym. Her hands firmly clasped together behind her back, the way she did when she was feeling sheepish. "Nothin' like Ballonlea or Wyndon, but it's home. Hope ya like it anyway."

The boy she was with surprised him at first. Bede, if he remembered correctly. The new young Fairy-Type Gym Leader who'd made a brilliant debut crashing the finals. It was reasonable now that Piers considered it—they were both around the same age and had just taken over their respective Gyms, so they had a lot in common. Bede shrugged and ran a hand through his hair, and replied, "I think it's a nice change of pace. It's not like I was able to stop by during the Gym Challenge, after all." The grin on his face quirked at the corner with a hint of irony, but he seemed to be taking his disqualification rather well. Opal's doing, most likely.

Even with the recent influx of tourists, Bede's pastel wardrobe stuck out like a sore thumb against Spikemuth's stark backdrop. Piers frowned a little, remembering how much of a match he'd been against the champion. While Marnie would probably have a great battle against him despite the disadvantage, Piers couldn't say the same about himself.

Suddenly, there was the image of a tinier Marnie flashing in his mind, innocently asking about boyfriends and getting married and having children. Piers had been so flabbergasted over it that he immediately declared that his little sister wasn't allowed to date any boy that couldn't defeat him in a proper battle. Marnie was content to accept that as a little girl and never brought it up again—and neither did he, too mortified in his overreaction. She wasn't... planning to make good on that half-forgotten promise just yet, was she? Piers would make sure to give Toxtricity some extra training as soon as he returned home, and reconsider his line-up. Dark-Types matched his personality and he'd embraced it as Spikemuth's Gym Leader, but now that he was retired, he could afford to branch out with a few more Poison-Types, surely...

The sound of Marnie's muffled laughter pierced through his thoughts. It was a shock to hear in public. Even more so when it had been caused by someone he didn't know.

Piers could hear Bede say, "Ha, and here I thought you couldn't smile," and see the way Marnie flushed in response. The faint pink was too light for all but the most seasoned of Team Yell to notice. Piers, who was used to the little changes in Marnie's face, could spot it from a distance, and felt a heavy stone grinding in the pit of his stomach.

And then—there was Bede's snide expression pointing away from hers, toward him. As though he was more than aware of Piers at the edge of an alleyway, trying to sneak a peek at his beloved sister.

Those smirking purple eyes sharpened, focused, and met his for a moment. Piers should have ducked into hiding the second Bede's delicate face tipped upward, searching, but now he was frozen, watching aghast as Bede slid his arm around the thin waist of his perfect little sister.

Piers wanted to yell at him to get his paws off her, but his voice didn't come out—not when she didn't shy away from his touch at the slightest. Instead she was all too eager to follow his direction as he ushered her into the Pok _é_ mon Center. Marnie with Bede? No way. He decided to push the thought from his mind and go home before Marnie noticed him, too. They were just... coworkers, friends. The way Piers had been with his fellow Gym Leaders when he started. Marnie was, after all, too good for Bede, or any Gym Leader for that matter (then what about an ex-Gym Leader who had run away from his post?).

It was late into the night before the turn of the lock. Piers was simultaneously elated and annoyed by it. What had taken her so long? Was she with Bede the whole time? He'd just barely avoided texting her every hour, asking her when she was planning to be back, and never once had she called him to check in, either. It wasn't like Marnie was going anywhere far, sure, but didn't she know how much he worried? Of course she did. Sometimes Piers was convinced Marnie did it on purpose, getting some secret pleasure out of making him squirm. Well, he was squirming.

He'd hardly been able to write anything. Piers almost wished he had just followed her and Bede around anyway—then he'd at least feel like he did something today. Though, to say he hadn't written _anything_ was untrue. He'd written a miserable dirge or five that he couldn't stand to look at, let alone put to music.

"I'm home," Marnie said, giving her customary knock to the door frame of his studio. "Oi." Piers could already picture the distaste on her face before he looked up from his desk to see her frown. "You been drinkin'?"

It was hardly fair of her to say it like that. The sun was already past the horizon, and Marnie might have had a bevvy of her own if she were home. Of course, Piers had been sipping at the tumbler for a few hours now, but it wasn't like she could know that for sure. "Well," he said, more sharply than intended, "ya took all day, Marn."

Rather than arguing, she let out sigh. "You should eat somethin' soon. I'm gonna take a shower and call it a night."

Piers drained the last centimetre of his glass and let out a long breath, trying to relax himself. He was getting all riled up over nothing—and obviously Marnie had been able to tell the same. By the time he went to wash his glass in the sink and consider putting something on his stomach, he could hear the soft spray of the shower going.

He really didn't want to leave things like this until morning. Even if he couldn't get anything out of Marnie to soothe his unfounded worries about Bede, he knew he should apologize for being a prat at least. He gave a light knock, then cracked open the door to the bathroom. The sense of privacy between them was never particularly strong, and by now Piers had seen her naked in just about every context it was possible for a person to.

That didn't mean he was immune to it, however—Piers could make out her body behind the frosted glass, the softness of her curves only amplified by the scattered light. The form paused, head tilting toward him. "Yeah?" Marnie called out. Even like this, Marnie was beautiful. It was normal for any guy her age to make a pass at her.

The thought stiffened the apology on his tongue. He swallowed, tried to wet his lips. "Didya already eat? I can, uh, cook up something if ya want?" A weak extension of the olive branch, but better than nothing.

Marnie's figured returned to motion, scrubbing at her arms and shoulder. "I'm fine," she said. "We went down to the pub earlier."

It was completely natural for her to have already eaten, but the way she said "we" so casually burrowed itself in his head, conjuring up footage of Bede and Marnie at her favorite spot by the docks, having a laugh over dinner. He must have loosened his lips too much earlier—now probing words were spilling out of his mouth. "That right? Did the Bede kid at least pay for it?"

Silence, just the water pooling at the bottom of the shower. Damn, why'd he have to say something like that? Then, Marnie's voice. "He offered, we went dutch." Suddenly, her tone was more suspicious. Accusing, even. "...Did I tell you I was meetin' Bede?" Piers wanted to laugh, what reason did _Marnie_ have to be suspicious of anything? It wasn't illegal for Piers to take a walk and see the two of them, practically arm in arm in the street.

"You're sayin' that like I'm not supposed t'know who your mates are. ...He _i_ _s_ just your mate, yeah?" Piers was no longer talking through the crack in the door, having fully stepped into the bathroom, where he could hear Marnie better over the sound of the shower.

It was clear as day as she let out another sigh, exasperated. He hated to hear the quiet frustration in her voice when she said, "You're such an idiot, Piers."

He should have said sorry already, left things where they lie, taken the sleepless night as the punishment for his paranoia. Instead, he went forward, no longer trusting the foggy silhouette to tell him the truth. He yanked open the shower door, needing to look at Marnie's teal-colored eyes directly to quiet the words of doubt echoing in his head.

"Big bro! Can't it wait!?" Marnie gasped out, eyebrows shooting straight up. There wasn't any shame or worry, only the disgruntled frown she made at the look on his face.

He wasn't sure if he more resembled a big brother who disapproved of his sister's taste in boys or one who'd just found his lover with another man. "You can't just expect me to accept it when you got some other guy all over you, Sis."

"You're off your gourd." Marnie went back to scrubbing with her striped washcloth, rubbing over the soft flesh of her side. Piers couldn't see anything there contradicting what she said, no marks left by smaller fingers than his, just pink skin, warmed by the water. "We're just friends."

The way that Marnie was so flippant about it still bothered him more than it soothed him. Piers knew very well the sorts of things pretty boys and girls got up to with their friends. "...With benefits?"

The glare Marnie leveled at him was a clear 'no', though she did not dignify the question with a verbal response. "Cut it out already. You're gettin' water all over the floor."

Standing there, clothes damp from the mist of shower, water pooling on the tile outside the stall, Piers knew how insane he was being—he'd written as much over and over again in the crumpled notes on his desk. But he knew he wouldn't be able to settle himself until he felt reassured. He stepped forward into the spray, and embraced Marnie tightly. She probably wanted to complain, but rather than struggling or pulling away, she gingerly wrapped her arms around his back. She was soft and slight against him, fitting better in his arms than she ever would in anyone else's. Piers's hands caressed the curve of her spine, finding the spot where Bede had held her before. He might have been able to feel her warmth, the ridge of her backbone, but Piers could feel the smoothness of her bare skin, the way she relaxed when he stroked the small of her back with his thumb.

Calmer now, he sheepishly mumbled, "Sorry, Sis. Ya forgive me for goin' a little crazy?"

Marnie let out an overly long sigh, more performative than serious. She raised her head, still shielded from the water by his body, and smirked at the sight of him dripping wet, rivets of water running over his shoulders. "I'm used to it now," she said. It made him feel a little bad, to know how true it was, but there was also relief in hearing it, that Marnie knew the worst of him and still let him cling to her anyway.

That thought in his mind, Piers knew he couldn't go another moment without kissing her. Gently, first starting with her forehead and cheeks, before pressing a quick peck to her lips, and, when Marnie did not push him away, Piers dove in again, deeper. The next sigh Marnie let out was whisper quiet, breathed into his mouth. Almost inaudible compared to the sound of the shower head, but Piers caught it, swallowed it, and pushed his tongue into Marnie's mouth to find the source.

Her fingers gripped the back of his shirt, and she oh-so sweetly kissed back. Piers instantly recognized the coy manner of her seduction, drawing him in, and eagerly sunk deeper into her kiss. While he had intended to corner Marnie in the shower, he didn't mean it physically—didn't mean it the way he did it now, stepping forward to press her slender body to the wall. He could feel her shiver as her back pressed against the cold tile, so naturally he rubbed at her waist, hoping to warm her up.

The kiss broke with a short gasp, warmth flowing through his body with such intensity now that he had her pinned. Had her right where he'd been wanting her all day, with nowhere else to go, staring up at him and him alone.

"You gonna let me wash in peace now?" Marnie asked finally. Piers blanched and jumped back. He fumbled with his words, trying to apologize yet again for acting out of line or more specifically, for the new round of possessive thoughts he'd let run wild. Before he could flee with a mumbled sorry, Marnie caught him by his shirt. Her face was flushed pink—no longer by the hot water. "Just kiddin'. I'm gonna be mad if you leave me hanging after that."

Marnie was already dragging him into another kiss before the words fully registered. Once they did, Piers was right back upon her, any sense of shame overtaken by the fact that Marnie was the closest to begging for him that she ever got. Her tongue pressed against his, licking along his teeth as his fingers crept between her legs, instinctively slipping between her wet thighs. Marnie gasped into his mouth, pulled back, and let out a quiet laugh. "Really drove you crazy today, huh?"

The note of delight in her voice, shine of amusement in her eyes quietly confirmed what Piers knew to be the ultimate truth, that Marnie liked watching him go out of his mind. "Made me feel like a damn fool, Sis," he muttered.

Her clit was already thickening with blood when Piers pressed his thumb against it, rubbing in small, quick circles. Marnie sucked in a breath, eyes fluttering shut. All the encouragement Piers needed to go on, delving his fingers inside her. Her body always opened up so easily for him. He couldn't help a small groan of arousal, knowing she was ready to take his cock in the same way. And even if she wasn't, a corner of him thought, she'd be ready for it when he pushed inside, reminded her who she actually belonged to.

Any other day, Piers would have took his time, fingering Marnie on his knee as he sucked her tongue, playing at her cunt until she came from it. But today, he had no such patience to spare.

"Ah— Bro!" Even Marnie seemed surprised when he lifted her by the hips without warning. Her legs went around his middle as she gripped onto his shoulders for balance, and he lowered her right onto his cock where she belonged. Her gasp of shock molded into sharp breaths of excitement and her heat swallowed him to the very base, making his head go blank.

"You really got me," a breath, "worked up today. Fuck, you feel so good." Like she was made for him, the missing piece he'd always been lacking. She leaned her head back against the wall as Piers began to thrust into her, hard. Marnie was always telling him that she wasn't made of glass, that she could take what he dished out if he wanted—and God, he wanted today. Her wet skin slapped against his own in a rushed rhythm and her fingers dug into his shoulders. Her breath raised on a high note, then lowered as she let out a moan. Piers could feel her cunt getting even slicker as he fucked her against the wall, until she was practically dripping. "You like how I feel inside you, Marnie?" he growled, as hungry for the answer as he'd been for her, as much as he hoped she hungered for him.

"Yeah," she said. One arm was clinging to him now as she fumbled at her clit with hurried fingers. "It feels—good. There, there, don't stop!" The order was completely unnecessary, but Piers loved hearing her demand it anyway, the way her voice took on a completely different harmony when she was close.

He chuckled and pressed his mouth to the curve of her extended neck. "You sound like you're already gonna come, Marn..."

The sharp sob as Marnie's hand moved faster was all he needed to know his suspicions were right. It was a little embarrassing to realize how close he was behind her, the thought of her coming around him egging him on. The anticipation of her cunt pulsing, contracting around him as he came inside her, left her dripping with his jizz. It was too hot. Too gratifying after all he'd been thinking today. Maybe the next time Marnie left to take a day on the town, he'd give her a warm load in her cunt and let her walk around like that, his semen slowly staining her panties. Maybe then she'd know better to go clinging to other guys when she had her big brother ready to give her whatever she needed.

"Fuck..." His fingers squeezed harder at her hips, and he knew it were going to bruise. Marnie was groaning against him as he rolled his hips, pushing himself deeper into her center, again and again. Slowing slightly, not for Marnie's sake—though the sound she made was perfect—but to stave off his orgasm just a few seconds longer. Just long enough for—

"Ohhh!" Marnie's breath caught, short nails catching in the cloth of his shirt. Her cunt clutched him tightly, the gasp on her lips transitioning into elongated moan. Piers didn't let up, couldn't, burying himself inside of her. He released a moan of his own and let his sister's tight cunt milk his cock, cradling her as he filled her up. A soft breathy laugh spilled from Marnie's lips, "Didn't think you'd actually come inside." Surprised, but not displeased. Between the two of them, Piers was the one always concerned about the possible consequences despite their precautions. But even Piers had a limit when it came to temptation, and Marnie had hit it three times over.

Marnie was trembling against him, knees quaking as Piers gingerly set her down. There was a flush on her round cheeks, her expression satisfied, despite having to lean back against the shower wall for balance. But even if his baby sis was content with that, Piers couldn't say the same. He'd recovered his breath, but looking at Marnie's heaving breasts was all he needed to gain a second wind. If this were another time, perhaps he would rub one out onto her stomach, or grind against her soft thighs. When Marnie felt particularly magnanimous, she'd take him into her mouth, tasting herself on his cock and swallowing every drop.

Instead, Piers twisted her around. He pulled her thin body against his, and slid himself right back inside her come-filled cunt.

"P-Piers," she whimpered, "don't, ah, 'm still, sensitive—"

"I know." Piers could feel it in the way she squirmed and quivered when he pressed his palm to her soft stomach and began to rub her sore clit. Marnie practically cried, twisting against his chest and gripping at his arm, trying to make the stimulation stop. Her cunt felt amazing around him like this—he barely had to move to have Marnie's muscles squeezing at him, pulsing in an unsteady rhythm. Marnie inadvertently did all the work for him, her body pushing back further onto his cock when she tried to wriggle away from his fingers.

She tugged more frantically at his wrist, but that only made Piers want to work harder. He laid his free hand across her chest, massaging the warm softness of a breast as he stroked her clit more roughly, in larger, quicker circles.

"Big Bro, ohhh," Marnie gave such a sweet little whine, and her body wracked with shivers. Piers rocked into her cunt, the punishing pace of his fingers only adding to her torment. Marnie nearly doubled over with a squeal as her grip on his arm went lax and she was twitching, coming again on his cock. But still, he didn't stop. "Big bro," she pleaded, "I'm sorry!"

A victorious feeling came over Piers at Marnie's apology. All that overreacting was suddenly justified, and he finally felt like he wasn't crazy. "So y'knew you were bein' a bad girl today, huh?"

Marnie's voice hit a high note as she wrenched her head back to look at him, face flushed with exertion and emotion. "That's cuz you were bad, too! Whaddya gonna do if some other guy makes a move when you're on tour?"

So it really was about the tour, like Piers had suspected. There was a little relief now, knowing that his relationship with Marnie wasn't actually in any trouble. He hugged her around the waist, pressing his nose to her hair. Her breath was still rough, but calmed as he held her tight. "Then you'll reject 'em... Yeah?"

Marnie tucked her chin to her chest, and Piers could practically see the pouty expression she was making by the disgruntlement in her voice. "Dunno."

Piers gently kissed at the back of her neck. She tried to seem reluctant at first, but when he found that sweet spot under her ear, she arched her back. "Then I'll have to make sure you remember your big brother no matter what," he murmured against her. Another kiss, at the delicate curve of her shoulder. "No one else is gonna fuck ya so hard you cry and make ya breakfast after, y'know?"

Marnie let out a little laugh at that one, despite herself. She tilted her head to the side, the way she always did when she wanted to be kissed. He did, deep with his breath and tongue, then harder, using his whole body, fingers kneading at the peak of her breast, plucking the stiff nipple. She melted against him wholly, warm and hot in his hands. Piers would make sure she never forgot him for a single moment, would ensure that the thought of straying would be as foolish and unsatisfying for her as it was for him. If he had to pamper her very being, in body and soul, every day until he departed, then he would.

He rubbed his cock against the soft, swollen lips of her cunt, holding back a little moan at the sensation. "Feel me, Sis? No one's gonna give it to you as good as me..."

Marnie's slight fingers squeezed around his cock. "Talkin' pretty big..."

"I'll be a man of action for ya." It was greedy to want to be inside her again, but every bit of patience had already been worn threadbare. He pinched at her waist and nudged his cock against her little cunt, still gaping from earlier.

"P-Piers," she gasped. Pulling at his hair, she dragged him into another kiss as he rutted into her.

"I'm gonna come inside you again," he breathed between kisses. "As many times as it takes for you to get it, Marn."

Rather than any words, Marnie let out another sweet noise of anticipation. Her legs were shaking so hard that Piers had to hold her by the waist, worried that she'd collapse onto the floor before he was through with her. This time when Piers couldn't hold it any longer, fucking upward into her heat, Marnie was panting hard, her whole body heaving with each breath. Piers's stomach clenched tight from the pressure as his second climax hit, and he filled his sister's cunt again.

Even without laying a finger on her sore clit, Marnie was there with him, cunt pulsing in orgasm as Piers thrust his softening cock in and out of her, determined to give her every bit of semen left. She took it well, all of it, until she could barely stay upright.

If it weren't for the fact that Piers was supposed to be Marnie's impressive older brother she couldn't live without, he would have joined her right on the floor. Instead, he worked up the energy to hoist her up and bring her to the nearby tub, where she could properly wash herself up without fear of falling over. Piers let himself down next to it, ignoring the puddle he was definitely making all over the bathroom floor. Marnie was quiet as she caught her breath, watching him. Piers avoided looking at her face and instead found himself staring right at her reddened cunt. He gulped, the stream of white leaking down the inside of her thigh causing a deep sense of satisfaction to rise up.

"So, you're gonna do that every day until you leave, huh?" Marnie said at length, a little grin in her voice.

"Ah, I mean," Piers tripped over his words, embarrassment clear as his eyes scanned the rest of her body, catching on the spots on her hips that were already turning red, where Piers had grabbed her hard. "If ya want."

"Yeah," she said, reaching out to tip up his chin, so he was directly meeting her eyes. "I want."


End file.
